Use of a hollow shell to contain a liquid center is well known in the art. The teachings of Liebich, U.S. Pat. No. 943,945, dated Dec. 21, 1909, discloses a hollow or empty body preferably made of sugar, enveloped or encased in an edible substance such as biscuit, chocolate, cake or sugar, which contained a liquor therein.
Similarly, Silver, U.S. Pat. No. 2,531,536, dated Nov. 28, 1950, teaches a liquid containing product but is more specifically concerned with a "flavor-bud" comprising a hard shell made of, among other things, a sizable quantity of anhydrous dextrose and some glucose, and a viscous liquid flavored center.
Kreuger et al., U.S. Pat. No. 2,580,683, dated Jan. 1, 1952, describes a capsule, capable of being filled with an aqueous solution, containing sugar in the gelatin employed to form the capsule.
In describing a unit dosage form of liquid or gel, Mackles, U.S. Pat. No. 4,260,596, dated Apr. 7, 1981, discloses a hard shell formed of two pieces, a cavity and a top, joined with a sealing material, encompassing a liquid or gel center, said shell utilizing mannitol rather than sugar as the shell forming ingredient.
Although there have been suggestions in the prior art of forming liquid center products encompassed to a shell comprising sugar, this procedure has found little favor in practice. Heretofore, molding of a sugar-comprised shell has demonstrated problems in crystallization during cooling, and stability and integrity due to moisture. Mackles, in particular, states that sugar is entirely unsuitable because molten sugar does not crystallize quickly on cooling, and cools to a tacky, amorphous state which sticks to the mold.
Furthermore, accurate dosages of the liquid or semi-solid center could not be achieved because of inaccurate methods of forming the shell and adding the liquid or semi-solid center.
It is therefore a primary object of the present invention to provide an edible unit dosage form which is capable of delivering an accurate dose of a liquid or semi-solid medicament.
It is a further object of this invention to encompass the liquid or semi-solid medicament in a relatively hard, unitary shell comprising sugar.
It is yet another object of this invention to provide a process for the manufacture of an edible unit dose form of an accurate amount of a liquid or semi-solid medicament encompassed in a relatively hard shell comprising sugar, specifically sucrose and/or glucose.